In discussing substance abuse, the chapter notes the prevalence of substance abuse among U.S. prison inmates and the opportunity for inmate drug treatment to impact the drug abuse problem generally, since most drug abusers spend at least some time in prison. Also discussed are the history of drug abuse treatment in the prison setting, types of substance abuse treatment offered in prison, the scope of State prison-based drug treatment, and evaluation of prison-based substance abuse treatment programs. In looking toward the 21st century, the chapter notes a recent trend by correctional administrators toward the adoption of comprehensive correctional models with strong rehabilitation and drug-treatment components. The section on HIV/AIDS in American prisons considers the prevalence of HIV/AIDS in prisons, HIV testing in prisons, housing and security, medical treatment, psychological and social services for HIV/AIDS afflicted inmates, the prevention of HIV transmission through education, and evaluations of such education programs. The authors advise that the medical and custodial needs of HIV/AIDS inmates will be one of the most, if not the single most, important considerations for correctional administrators well into the 21st century. The section on tuberculosis addresses the transmission of TB, testing for TB, the prevalence of TB infection and active TB in prison, co-infection with HIV and TB, and the treatment and prevention of TB in prisons. Also considered are multiple drug resistant TB and ways of improving the TB situation in prisons into the 21st century. Study questions and 57 references